Baseline Setup & Tuning for Cal-Tracs

Cal-Tracs is the best suspension system for factory equipped rear leaf spring suspension like on our A, B, or E-Body Mopars! 

Either you are setting up a suspension for the first time OR need some help at the track, use our quick guide and keep it in your race car trailer for easy reference. This guide is written for double adjustable shocks, single/non-adjustable shocks are not recommended.

The "Rules":
Must have a free moving FRONT & REAR suspension, ZERO bind of any kind.
Calvert's Mono-Leaf or similar springs are highly recommended.
Cal-Tracs REQUIRE at least 5" of front end travel, if you can't get enough front end travel Cal-Tracs WILL NOT WORK!
Double Adjustable shocks required, need to be able to control rebound & compression independently of each other.
Racer Note: Once you’re over 600 HP, cheap shocks make suspension tuning a nightmare. Double-adjustables make all the difference when you have the independent control of rebound and compression.


Setting Up Baseline:
Set bars on the bottom bracket hole & set pre-load to 0 (front pivot bar just touching the leaf springs, some people use a dime for this measurement between the pivot bar and leaf spring)
Set front shocks to full loose; example: (90%-Compression /10%-Rebound)
Set rear shocks to tightest extension setting; We want a soft hit for baseline purposes.
Set rear shocks to a 70-80% rebound; )Example: If you have 16 settings, start at 12. If you have a -/+ on your shock knob, think of full + as 100%.)

Rear Shock - Basic Principles for Leaf Spring Setups:
Compression controls how hard it is to collapse the shock OR controls how long the tire will hit for (think holding that body/tire separation for longer/shorter)
Rebound controls how hard it is to extend the shock OR controls how hard the tire hits on the starting line (think how much body/tire separation we get initially to work with)

- If you are running bias-ply slicks, this baseline should be OK. The goal with slicks is not to completely crush the side wall on the hit and have a "controlled" spin IMO... I have very limited experience on slicks. Maybe someone else can chime in here!

- If you are running radials, they like the hit HARD with such a stiff sidewall. Loosen extension a 2-3 clicks from the baseline recommendation to get a harder hit! Radials like it.

You are now setup for a test pass! Go make a pass and take note what happens on the starting line when the car takes off. Definitely helps to have a friend recording your run from the starting line!

- Hooks & Goes Straight: GOOD TO GO! Loosen rear extension until 60" ft stops getting better. Compression can also be used if you are happy with the hit but would like to extend it out to get any more 60 ft gains. Every car is a bit different, but going to test and tunes and collecting good data is your best friend here for max 60 ft gains.

- Doesn't hook at all: Consider either loosening extension for a harder hit or moving your Cal-Trac bar to the upper hole to move the instant center more towards the back of the car. (Thus making the tire hit even harder).

- Hook & Pull a Big Wheelie: Tighten front shocks (Only time we ever do this.)

- Hook & Spin after 20-30 ft: Loosen rear shock extension, we aren't hitting the tire hard enough.

- Hook & Pull Left or Right: Add pre-load to the side that it pulls to until it leaves straight. Only make little adjustments, this shouldn't take much to correct. (Think 1/8-1/4 turns at a time)

- Quick Reference Guide -

Softest Hit: Lower Hole - 0 pre-load - **This was the baseline**

Soft Hit: Lower Hole - 0-1.5 turns of pre-load

Hard Hit: Upper Hole - 0 pre-load

Hardest Hit: Upper Hole - Up to 1.5 turns of pre-load

Pre-Load Note: Do not exceed 1.5 turns as damage to the leaf spring can occur.

Good Luck!